The specific aims of this proposal are: 1. To characterize EBNA as a protein including the elucidation of its primary amino acid sequence; 2. To study the binding of EBNA to DNA and to protein; 3. To prepare a monospecific EBNA heteroantiserum; 4. To develop radioimmunoassays for EBNA and EBNA antibody; 5. To study the possible heterogeneity of EBNA; 6. To study the functions of EBNA in their relationship to transformation of human B lymphocytes.